Why do scientists want to revive the Tasmanian tiger?

A radical idea to support recovery Ecosystems The damaged gains strength: Resurrection Species that are extinct and return them to nature. Proponents of “de-extinction” argue that by bringing back species that played an important ecological role in their former habitats, entire regions could benefit.

The lab-created animals would not be the exact species that became extinct, but the hybrids with DNA filled in by living relatives. The most famous de-extinction project is an attempt to bring back a copy of woolly mammoth, links its genome to the DNA of the Asian elephant. The work is a long-term project by Harvard geneticist George Church, who recently co-founded the $75 million privately funded bioscience company Colossal to accelerate research.

Colossal recently announced that it has partnered with a group of researchers from the University of Melbourne (Australia) to work on the extinction of another animal: the Tasmanian tiger, also known as the Tasmanian tiger. This Australian marsupial predator became extinct less than a century ago.

We are working on [desextinção d0 tilacino] I’ve been in my lab for about 10 years, but in partnership with Colossal, they have this incredible wealth of knowledge, this huge amount of technology that they can bring to the table with the work that we’ve been doing. University of Melbourne Thylacine Restoration Lab.

The scientists behind the project believe that bringing this creature back would restore the ecological balance of Tasmania by reintroducing a predator at the top of the food chain, keeping other animals in check. The work could also help advance technology, such as genetic engineering tools and artificial wombs, that could support other conservation work.

But skeptics argue that the challenges of genetic engineering that thwarted previous attempts to bring back Tasmanian tigers remain significant barriers, and that extinction work could put a brake on other conservation efforts to help the now-threatened animals. The Moral To bring back an extinct creature is also very discussed.

“I have no difficulty in bringing Tasmanian tigers back into modern ecosystems. There is still plenty left to do,” says Chris Johnson, an ecologist at the University of Tasmania who studies extinction. “But we’ve been through this before. De-extinction Thylacine has been a topic in Australia for at least 20 years, and nothing has come of it.”

The Tasmanian tiger is a lost predator

Tasmanian tigers (Thylacinus cynocephalus) marsupial, that is, she carried her young in a bag like a kangaroo. Tasmanian tigers It comes from the Greek word tholakos Which means bag – but it looked more like a skinny dog ​​with a thick, stiff tail.

The animal was nicknamed the Tasmanian tiger because of its distinctive streak under its back. he is It roamed the earth for millions of yearsprobably since the beginning of the Pleistocene, which includes much of Australia and New Guinea.

The thylacine was semi-nocturnal and mostly loner and ambush predator, hunting small to medium-sized prey at night. At some point in the past few thousand years, the animal disappeared from New Guinea and the Australian mainland, most likely Because of human hunting and competition with the dingoWhat is it It was brought from Asia to Australia about 4000 years ago. For hundreds of years, the island of Tasmania has been the animal’s last resort.

last of its kind known, A tiger named Benjamin, died in September 1936 at the Beaumaris Zoo in Hobart, Tasmania, just two months after his species was granted protected status. Since then, many people have claimed to have seen Tasmanian tigers, and some researchers have argued that the animal could have lived longer than previously thought. No confirmed sightings have occurred since 1936, but the species was declared extinct by the International Union for Conservation of Nature only in 1982.

Today, Tasmania’s ecosystems are threatened by the disappearance of its ‘tiger’. The loss of a predator at the top of the food chain left a large abundance of small macropods, a family of marsupials, such as the red-necked kangaroo and Tasmanian padimelons. These animals have damaged the native vegetation due to overgrazing, resulting in ecological instability and threatening other herbivores.

Restoring the Tasmanian tiger could, in theory, help keep these tiny animals in check. Predators at the top of the food chain also help contain the spread of diseases among their prey, such as the Tasmanian devil’s face tumor, a transmissible cancer that is currently spreading among these animals. But reviving a species from extinction presents major scientific challenges.

Genetic engineering of an extinct creature

Baske remembers that any extinction project must begin with the closest living relative of the animal in question. The closest living relative of the Tasmanian tiger is the numbat, a small insect-eating marsupial native to Western Australia whose genetic sequence was decoded earlier this year.

Numbats and thylacines share an ancestor about 40 million to 35 million years ago, and the two species share Up to 95% of your DNA. So the numbat genome could serve as a model that could be modified, using gene-editing technology like Crispr, to resemble the genome of the extinct Tasmanian tigers, which were First series in 2017 using museum samples.

“We are very good at making large pieces of DNA, so we genetically engineered this cell. [numbat] live to turn it into the genome of the Tasmanian tiger,” Baske explains. “Now, you just have to put that cell back into a living animal.”

The genomes available for Tasmanian tigers are fragmented, however, filling some of the gaps remains a challenge. The genetic modification of the Tasmanian tiger may be more complex than the woolly mammoth, for example, because the latter is more closely related to its living mold, the Asian elephant, than the Tasmanian tiger is to the numbat.